A federal judge may block what would be Nevada’s first execution in 15 years. U.S. District Court Judge Richard Boulware says he’ll need more time to determine whether the undisclosed drugs scheduled to be used in the lethal injection of Zane Floyd next month are constitutional. Floyd was sentenced to death for the killings of four people, and the shooting of a fifth person inside a Las Vegas supermarket in 1999. A court hearing is scheduled for Monday in the case.